The patent application of Frederick J. Kozacka, filed 03/07/77; Ser. No. 775,248 for ELECTRIC ALL PURPOSE FUSE suggests to limit the axial spacing between a plurality of parallel connected fusible elements to a critical distance at which an electric breakdown can occur, but a self-sustained high current discharge, or arc, cannot occur. The flashover damages the fusible elements, and results in break formation at the damaged point or points by additional i.sup.2.r losses at this point, or points, thus establishing the required series breaks.
This process has a number of limitations. While it is desirable to maximize the axial spacing between parallel connected turns of the helical windings of a fusible element, Kozacka calls for reduction of that spacing to a critical value. Another limitation of Kozacka resides in the fact that the point where the breakdown will occur is not pre-determined, but can occur randomly, at any point of the fusible elements. It may, for instance, occur near one of the terminal elements where an arc should not be initiated.
The primary object of this invention is to provide electric fuses which are not subject to the above limitations. Other objects will become apparent as this specification proceeds.